Digital-to-analog converters are used in flash memories for generating the biasing voltages required during reading, programming, and verifying operations for memory cells. In particular, these memory operations are rather complex, and the voltages required may vary considerably, i.e. a wide range of voltage levels with values very distant from one another. For example, an erase operation may be applied to the gate terminal of an addressed memory cell a voltage ramp, the erase operation having steps of 0.3 V between a minimum voltage of 4 V up to a maximum voltage of 10 V, or else, a so-called “soft programming” operation may be applied to the gate terminal of an addressed memory cell a voltage ramp, the “soft programming” operation having steps of 0.125 V between a minimum voltage of 2.5 V up to a maximum voltage of 7 V.
Furthermore, rapid transitions are generally possible between the various voltage levels generated, both in charging and discharging conditions; the capacitive load conditions are also variable. For example, the capacitive load conditions may vary between a minimum load of 2-3 pF up to a maximum load of 400 pF. The digital-to-analog converter, and in particular a corresponding amplifier circuit that generates the biasing voltages required during the various memory operations, may have stringent requirements from the standpoint of electrical performance.